Earth's Busy Neighborhood

ACC's Small Object Report for 6-12 November 2006

A semi-automated report compiled on 12 November 2006 at 2359 UTC

Twelve small asteroids reported in the last 168 hours, during which none were newly discovered.
Currently 1,151 NEAs are listed with H>22.0 by JPL and/or the MPC (967 are listed as such by both).
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Editor's note: As asteroids go, "small" is defined as having an
absolute magnitude (brightness) calculated at greater than H=22.0, which
converts very roughly to a diameter under 135 meters.
No matter how close they come to the Earth, the astronomical community
does not classify such objects as "potentially hazardous." However, as
demonstrated by the mile wide (1.6 km.) Barringer Crater in Arizona, blasted
out by a "small" asteroid some 50,000 years ago, there are asteroids too small
to be labeled "potentially hazardous" that actually could cause severe local
damage. These are sometimes called "Tunguska-class objects" (TCOs), after the
1908 event probably caused by a comet fragment or asteroid too small to be
classified today as hazardous but packing enough wallop to flatten a Siberian
forest area the size of a large city.
NEODyS in December 2005 changed its main Risk page to classify "Objects too
small to result in heavy damage on the ground" as having "absolute
magnitude > 25," which corresponds to perhaps 35 meters wide.
And JPL two months earlier started flagging (with a blue background) risk-listed
objects of "Estimated diameter 50 meters or less" as "not likely to
cause significant damage in the event of an impact, although impact damage
does depend heavily upon the specific (and usually unknown) physical
properties of the object in question."
Small asteroids that come close enough to Earth to be seen have significant
potential for scientific study today, and for exploration and
exploitation in the future. They present a sampling of distant asteroid
populations and a few may be remnants of the event that created the
Earth-Moon system.
Some of these objects are discovered while close to Earth moving across the sky
quite quickly, when they are called "FMOs" or "VFMOs" (very fast moving objects).
The discovery and follow-up tracking of asteroids with H>22.0 represents
some of the most difficult and very best observing work being done today by
amateur and professional astronomers around the world, and the page you are
reading is dedicated to recognizing their ongoing successes.

Nov. 12: Sunday's Daily Orbit Update (DOU) MPEC 2006-V42 reports recent observations of six small asteroids. The Mount Lemmon Survey (MLS) in Arizona made the second observation of 1998 HG49 on its third opposition, bringing this year's arc to 118.5 days. MLS also added about fourteen days to what had been a 32-day observing arc for 2006 SP198 and about 22 days to 2006 TO's eighteen-day arc, and together with Sandlot Observatory in Kansas extended 2006 UP's eleven-day arc by about fifteen days. The Spacewatch 1.8-meter telescope added about fourteen days to 2006 SB142's former 30-day observing arc. And Desert Moon Observatory in New Mexico kept an eye on 2006 UF.
Also in the DOU is observation of 2005 EZ223 reported from the Crimean Astrophysical Observatory in the Ukraine from April 6th last year, extending the former 23-day observing arc by almost seventeen hours. 2005 EZ223 was discovered by the Catalina Sky Survey in Arizona on 14 March 2005.

Nov. 11: Saturday DOU MPEC 2006-V36 reports observations of two small asteroids yesterday and two more in recent years. 2006 UE has had about fifteen days added to its eleven-day observing arc from work at the Spacewatch 1.8m telescope in Arizona yesterday morning and Pla D'Arguines Observatory in Spain last night. And NEAT's Mt. Palomar telescope in southern California tracked 2006 UC185.
Some sleuth or sleuths have found 2002 XB40 from NEAT/Palomar from 10 December 2002, shortly after this object was first noticed by LINEAR in New Mexico. It was last reported observed eighteen days later in observations coded to Tim Spahr at Whipple Observatory in Arizona.
2004 VP was discovered on 3 November 2004 with the Spacewatch 0.9-meter telescope in Arizona and had been last reported observed on December 1st, by Powell Observatory in Kansas. Today 34 positions spanning two and a quarter hours on 5-6 April of the next year are reported from the Crimean Astrophysical Observatory in the Ukraine.

Nov. 10: Friday DOU MPEC 2006-V35 reports observations of three small asteroids. In southern California NEAT's Mt. Palomar telescope and Jim Young at Table Mountain Observatory added about seven days to the five-day observing arc of 2006 UC185, Desert Moon Observatory in New Mexico added about fourteen days to 2006 UF's ten-day arc, and Great Shefford Observatory in England added eight days to 2006 VB's one-day arc.

Nov. 7-9: The DOU MPEC on Tuesday carried recent observation of only one asteroid, and it wasn't classified as small. There was more activity reported in Wednesday's DOU, but no small asteroids, and Thursday's three recently-observed asteroids also weren't small. This situation is normal following a full Moon, but observing activity may have been affected by the Minor Planet Ephemeris Service being unavailable from sometime yesterday into today and for a time on the 7th. See the MPC Status Page for more about that. That page itself was also out and now says "We expect that there will be more problems in the coming days." There are alternate ephemeris services but this one is probably the most used by NEO observers. It is central to the NEO discovery confirmation process that is just starting up again today as interference from the Moon decreases.

Nov. 6: Monday's DOU MPEC 2006-V17 reports observation of one small asteroid, of 2006 UA216 from Schiaparelli Observatory in Italy on Saturday.